:root {
    --primary: #2980FE;
    --primary-dark: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1f2937;
    --muted: #64748b;
    --light: #f5f7fb;
    --line: #e5eaf2;
    --white: #ffffff;
    --radius: 24px;
    --shadow: 0 16px 45px rgba(31, 41, 55, 0.08);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #f7f9fd;
    line-height: 1.75;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

p {
    margin: 0 0 14px;
}

h1, h2, h3 {
    margin: 0 0 14px;
    line-height: 1.25;
    color: #111827;
}

h1 {
    font-size: clamp(2rem, 8vw, 4.5rem);
    letter-spacing: -0.04em;
}

h2 {
    font-size: clamp(1.65rem, 5vw, 2.8rem);
    letter-spacing: -0.03em;
}

h3 {
    font-size: 1.2rem;
}

.container {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(229, 234, 242, 0.9);
}

.header-inner {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.logo, .footer-logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #111827;
}

.logo img, .footer-logo img {
    width: 38px;
    height: 38px;
    object-fit: contain;
    border-radius: 12px;
}

.nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
    color: #111827;
    font-size: 1.2rem;
}

.site-nav {
    position: absolute;
    top: 72px;
    left: 16px;
    right: 16px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}

.site-nav.open {
    display: flex;
}

.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #475569;
    font-weight: 700;
    font-size: 0.94rem;
}

.site-nav a.active,
.site-nav a:hover {
    color: var(--primary);
    background: #eef5ff;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 26px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41, 128, 254, 0.26);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 18px 34px rgba(23, 104, 232, 0.3);
}

.text-link {
    color: var(--primary);
    font-weight: 800;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 999px;
    color: var(--primary);
    background: #eef5ff;
    font-size: 0.86rem;
    font-weight: 800;
    margin-bottom: 16px;
}

.section {
    padding: 64px 0;
}

.section-muted {
    background: #eef3fb;
}

.section-head {
    max-width: 760px;
    margin-bottom: 30px;
}

.section-head.center {
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}

.section-head p,
.lead {
    color: var(--muted);
    font-size: 1.05rem;
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    padding: 62px 0 74px;
    color: #fff;
    background: var(--gradient);
}

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    pointer-events: none;
    border-radius: 999px;
}

.vpn-network-hero::before {
    width: 560px;
    height: 560px;
    top: -220px;
    right: -160px;
    background: rgba(255, 255, 255, 0.13);
}

.vpn-network-hero::after {
    inset: 0;
    background-image:
        radial-gradient(circle at 15% 26%, rgba(255,255,255,.36) 0 2px, transparent 3px),
        radial-gradient(circle at 70% 32%, rgba(255,255,255,.34) 0 2px, transparent 3px),
        radial-gradient(circle at 86% 68%, rgba(255,255,255,.32) 0 2px, transparent 3px),
        linear-gradient(125deg, transparent 0 18%, rgba(255,255,255,.16) 18% 18.25%, transparent 18.5% 100%),
        linear-gradient(30deg, transparent 0 55%, rgba(255,255,255,.14) 55% 55.25%, transparent 55.5% 100%);
    opacity: .75;
}

.hero-grid {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr;
    gap: 36px;
    align-items: center;
}

.hero-content h1,
.hero-content h2,
.hero-content p {
    color: #fff;
}

.hero-content .lead {
    color: rgba(255,255,255,.86);
    max-width: 640px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 14px;
    margin: 26px 0;
}

.hero-note {
    color: rgba(255,255,255,.82);
    font-weight: 700;
}

.security-tags,
.hero-status-list,
.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.security-tags span,
.hero-status-list span,
.tag-row span {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 6px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.24);
    color: #fff;
    font-size: 0.9rem;
    font-weight: 700;
}

.hero-visual {
    position: relative;
    min-height: 360px;
    display: grid;
    place-items: center;
}

.hero-device {
    position: relative;
    z-index: 2;
    width: min(430px, 88vw);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255,255,255,.18);
    border: 1px solid rgba(255,255,255,.24);
    box-shadow: 0 32px 80px rgba(20, 27, 72, 0.24);
}

.hero-device img {
    width: 100%;
    border-radius: 24px;
}

.status-card {
    position: absolute;
    z-index: 3;
    display: none;
    padding: 12px 14px;
    border-radius: 18px;
    background: rgba(255,255,255,.92);
    color: #111827;
    box-shadow: 0 18px 42px rgba(28, 35, 76, 0.18);
    font-weight: 800;
    font-size: .92rem;
}

.status-card small {
    display: block;
    color: var(--muted);
    font-weight: 700;
}

.status-card.one { top: 20px; left: 0; }
.status-card.two { top: 78px; right: 0; }
.status-card.three { bottom: 78px; left: 10px; }
.status-card.four { bottom: 20px; right: 20px; }

.node-overview {
    margin-top: -36px;
    position: relative;
    z-index: 5;
}

.node-card-grid,
.feature-grid,
.risk-grid,
.faq-grid,
.related-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
}

.node-card,
.feature-card,
.risk-card,
.faq-item,
.related-card,
.step-card,
.info-card,
.policy-card,
.tip-box,
.check-card,
.guide-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 10px 30px rgba(31, 41, 55, 0.05);
}

.node-card strong,
.card-label {
    display: inline-flex;
    margin-bottom: 12px;
    padding: 5px 10px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--primary);
    font-size: .82rem;
    font-weight: 900;
}

.node-card p,
.feature-card p,
.risk-card p,
.faq-item p,
.related-card p,
.info-card p,
.policy-card p,
.step-card p,
.guide-card p {
    color: var(--muted);
}

.split,
.vpn-connection-section,
.global-nodes-section,
.high-speed-section,
.privacy-protection-section,
.multi-device-section,
.encryption-protocol-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
    align-items: center;
}

.visual-card {
    position: relative;
    overflow: hidden;
    border-radius: 32px;
    background: #fff;
    border: 1px solid var(--line);
    padding: 18px;
    box-shadow: var(--shadow);
}

.visual-card.gradient-frame {
    background: linear-gradient(135deg, #ffffff, #eef5ff);
}

.feature-list,
.clean-list {
    list-style: none;
    padding: 0;
    margin: 18px 0 0;
    display: grid;
    gap: 10px;
}

.feature-list li,
.clean-list li {
    position: relative;
    padding-left: 26px;
    color: #475569;
}

.feature-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 10px;
    width: 10px;
    height: 10px;
    border-radius: 999px;
    background: var(--primary);
    box-shadow: 0 0 0 5px rgba(41,128,254,.12);
}

.global-nodes-section {
    position: relative;
    padding: 26px;
    border-radius: 32px;
    background:
        radial-gradient(circle at 24% 24%, rgba(41,128,254,.14), transparent 28%),
        radial-gradient(circle at 80% 34%, rgba(123,78,241,.14), transparent 24%),
        #fff;
    border: 1px solid var(--line);
    overflow: hidden;
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(90deg, rgba(41,128,254,.08) 1px, transparent 1px),
        linear-gradient(0deg, rgba(41,128,254,.08) 1px, transparent 1px);
    background-size: 56px 56px;
    pointer-events: none;
}

.global-nodes-section > * {
    position: relative;
    z-index: 2;
}

.speed-lines {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.speed-line {
    display: grid;
    grid-template-columns: 86px 1fr;
    gap: 12px;
    align-items: center;
    color: #475569;
    font-weight: 800;
}

.speed-bar {
    height: 10px;
    border-radius: 999px;
    background: #dde8f9;
    overflow: hidden;
}

.speed-bar span {
    display: block;
    height: 100%;
    border-radius: inherit;
    background: var(--primary);
}

.privacy-panel,
.tech-panel,
.safety-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 32px;
    padding: 24px;
    box-shadow: var(--shadow);
}

.privacy-box {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
    margin-top: 18px;
}

.privacy-box div,
.tech-item {
    padding: 16px;
    border-radius: 18px;
    background: #f7faff;
    border: 1px solid #e0ebfb;
}

.no-log-policy-section .feature-grid {
    margin-top: 10px;
}

.process-steps {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.step-card {
    position: relative;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 12px;
    background: var(--primary);
    color: #fff;
    font-weight: 900;
    margin-bottom: 12px;
}

.risk-card {
    border-left: 4px solid var(--primary);
}

.risk-card strong {
    display: block;
    color: #111827;
    margin-bottom: 6px;
}

.cta-section {
    overflow: hidden;
    position: relative;
    padding: 64px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
}

.cta-section::after {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    border-radius: 999px;
    right: -160px;
    bottom: -220px;
    background: rgba(255,255,255,.16);
}

.cta-section .container {
    position: relative;
    z-index: 2;
}

.cta-section h2,
.cta-section p {
    color: #fff;
}

.cta-section p {
    max-width: 680px;
    margin: 0 auto 24px;
    color: rgba(255,255,255,.86);
}

.page-hero {
    padding: 54px 0 40px;
    background: linear-gradient(180deg, #eef5ff 0%, #f7f9fd 100%);
}

.page-hero .container {
    max-width: 920px;
}

.content-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 26px;
    align-items: start;
}

.content-main {
    display: grid;
    gap: 20px;
}

.side-panel {
    display: grid;
    gap: 16px;
}

.article-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 24px;
    box-shadow: 0 10px 30px rgba(31,41,55,.05);
}

.article-card p {
    color: #475569;
}

.download-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 32px;
    padding: 28px;
    text-align: center;
    box-shadow: var(--shadow);
}

.step-list {
    counter-reset: step;
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 14px;
}

.step-list li {
    counter-increment: step;
    position: relative;
    padding: 16px 16px 16px 58px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
    color: #475569;
}

.step-list li::before {
    content: counter(step);
    position: absolute;
    left: 16px;
    top: 16px;
    width: 28px;
    height: 28px;
    display: grid;
    place-items: center;
    border-radius: 10px;
    background: var(--primary);
    color: #fff;
    font-weight: 900;
}

.faq-list {
    display: grid;
    gap: 16px;
}

.faq-item h2,
.faq-item h3 {
    font-size: 1.08rem;
}

.site-footer {
    background: #111827;
    color: #cbd5e1;
    padding: 48px 0 22px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
}

.footer-logo,
.footer-links h3 {
    color: #fff;
}

.footer-brand p {
    max-width: 360px;
    color: #94a3b8;
}

.footer-links {
    display: grid;
    gap: 8px;
}

.footer-links a {
    color: #cbd5e1;
}

.footer-links a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.12);
    margin-top: 32px;
    padding-top: 18px;
    color: #94a3b8;
    font-size: .9rem;
}

@media (min-width: 640px) {
    .node-card-grid,
    .feature-grid,
    .risk-grid,
    .faq-grid,
    .related-grid,
    .process-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
    .status-card {
        display: block;
    }
}

@media (min-width: 900px) {
    .nav-toggle {
        display: none;
    }
    .site-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        justify-content: flex-end;
        gap: 2px;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
    }
    .site-nav a {
        font-size: .88rem;
        padding: 9px 10px;
    }
    .hero-grid,
    .split,
    .vpn-connection-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section {
        grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    }
    .global-nodes-section {
        grid-template-columns: .9fr 1.1fr;
        padding: 38px;
    }
    .node-card-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }
    .risk-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .process-steps {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
    .content-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
    }
    .footer-grid {
        grid-template-columns: 1.4fr repeat(3, 1fr);
    }
}

@media (min-width: 1080px) {
    .site-nav a {
        font-size: .92rem;
        padding: 9px 12px;
    }
}